The present invention relates to an apparatus for fusion splicing optical fibers to each other.
When separated single mode light optical fibers are connected to each other, the end portions of the optical fibers are opposed to each other, and fusion spliced. In this case, it is necessary to accurately match the axes of the optical fibers before they are fusion spliced. Therefore, the matched state of the axes of the optical fibers is confirmed by a visual observation with a microscope or a TV camera. The axes of the optical fibers are matched individually in both vertical and horizontal directions.
In FIG. 1, reference numeral 10 designates a base, four posts are mounted on the base 10 (the posts disposed in front of and behind this paper are not shown, but the posts disposed at the right and left sides are shown in FIG. 1), and a planar base 14 is horizontally mounted on the posts 12. A pair of V-shaped slot blocks 16 which can be finely adjusted in a horizontal direction (in a X direction in FIG. 2) and in a vertical direction (in a Y direction in FIG. 2), and an optical fiber supporting unit 18 are mounted on the base 14. A controller 20 (such as a motor for moving the block 16) is disposed under the base 14, and a case 22 which extends between the base 10 and the base 14 is covered on the periphery of the controller 20.
A stand 24 is mounted on the base 10, and a microscope 26 is mounted on the stand 24 through an arm 25, disposed directly above the blocks 16. The position of the microscope 26 is not fixed, but can be adjusted when it is being used.
In order to observe the matching of the axes of the optical fibers in the horizontal direction of the cores of the optical fibers, the microscope 26 must be, as shown in FIG. 2, disposed on a rectilinear line for coupling between a light source 32 (provided directly under an optical fiber 30) and the optical fiber 30. The microscope 26 must also be adjusted so as to focus the cores of the optical fiber 30 on the line. Then, in order to observe the matching of the axes of the optical fibers in the vertical direction of the cores of the optical fibers, the microscope 26 must be disposed on the optical path of the light ray 15 from a light source 34, reflected by a mirror 36 through the X direction of the optical fiber 30, and the microscope 26 must be adjusted to the position so as to focus the core of the image 30' of the optical fiber 30. Thus, to observe the matching of the axes of the optical fibers, the position of the microscope 26 must be moved and adjusted several times.
As understood from FIG. 1, in the case of the above-described conventional microscope, the microscope 26 is mounted at the end of the arm 25 extended from, and above, the top of the long stand 24. Thus, even if a small force is applied to the apparatus, it affects the microscope 26 to a considerably large degree. Therefore, when the apparatus is contacted or a vibration is applied to the apparatus after the microscope is adjusted, the adjusted state of the microscope is immediately disordered, and the microscope must be again adjusted.
Particularly, when a TV camera 27 is fixed, as shown in FIG. 3, to the microscope 26, the weight applied to the arm 25 greatly increases. Thus, the movement of the apparatus, due to the external force, is large. In the apparatus shown in FIG. 3, an image is analyzed by a processor 28 as shown in FIG. 4, a fine adjustment unit 29 is moved on the basis of the result, and the position of the microscope 26 is automatically adjusted. However, in this case, the microscope 26 must be moved simultaneously with the TV camera 27. Therefore, the inertial effect is further increased as compared with the construction of the apparatus shown in FIG. 1 with the result that the starting and stopping of the unit cannot be smoothly conducted. The output of the fine adjustment unit 29 must also be increased. Incidentally, reference numeral 38 designates a TV monitor.
Further, in the conventional apparatuses shown in FIGS. 1 to 4, the microscope 16 and the TV camera 27 are exposed above the blocks 26. Thus, after the microscope is adjusted, an operator might carelessly contact the apparatus, and the microscope might be disordered.